Change main file tests to define sources inline

The tests are structured quite differently now but I think the new, smaller test cases cover all the interesting cases from the old test.

Author: ahoppen

Sources/SKTestSupport/INPUTS/MainFiles/a.swift

@@ -113,11 +113,13 @@ public class MultiFileTestWorkspace {
   /// Opens the document with the given file name in the SourceKit-LSP server.
   ///
   /// - Returns: The URI for the opened document and the positions of the location markers.
-  public func openDocument(_ fileName: String) throws -> (uri: DocumentURI, positions: DocumentPositions) {
+  public func openDocument(_ fileName: String, language: Language? = nil) throws -> (
+    uri: DocumentURI, positions: DocumentPositions
+  ) {
     guard let fileData = self.fileData[fileName] else {
       throw Error.fileNotFound
     }
-    let positions = testClient.openDocument(fileData.markedText, uri: fileData.uri)
+    let positions = testClient.openDocument(fileData.markedText, uri: fileData.uri, language: language)
     return (fileData.uri, positions)
   }
 

Sources/SKTestSupport/INPUTS/MainFiles/b.swift

@@ -78,6 +78,10 @@ public class SwiftPMTestWorkspace: MultiFileTestWorkspace {
       "-Xswiftc", "-index-ignore-system-modules",
       "-Xcc", "-index-ignore-system-symbols",
     ]
-    try await Process.checkNonZeroExit(arguments: arguments)
+    var environment = ProcessEnv.vars
+    // FIXME: SwiftPM does not index-while-building on non-Darwin platforms for C-family files (rdar://117744039). 
+    // Force-enable index-while-building with the environment variable.
+    environment["SWIFTPM_ENABLE_CLANG_INDEX_STORE"] = "1"
+    try await Process.checkNonZeroExit(arguments: arguments, environment: environment)
   }
 }

Sources/SKTestSupport/INPUTS/MainFiles/bridging.h

@@ -265,54 +265,4 @@ final class BuildSystemTests: XCTestCase {
     let refreshedDiags = try await testClient.nextDiagnosticsNotification()
     XCTAssertEqual(refreshedDiags.diagnostics.count, 2)
   }
-
-  func testMainFilesChanged() async throws {
-    let ws = try await mutableSourceKitTibsTestWorkspace(name: "MainFiles")!
-    let unique_h = ws.testLoc("unique").docIdentifier.uri
-
-    try ws.openDocument(unique_h.fileURL!, language: .cpp)
-
-    let openDiags = try await ws.testClient.nextDiagnosticsNotification()
-    XCTAssertEqual(openDiags.diagnostics.count, 0)
-
-    try ws.buildAndIndex()
-    let diagsFromD = try await ws.testClient.nextDiagnosticsNotification()
-    XCTAssertEqual(diagsFromD.diagnostics.count, 1)
-    let diagFromD = try XCTUnwrap(diagsFromD.diagnostics.first)
-    XCTAssertEqual(diagFromD.severity, .warning)
-    XCTAssertEqual(diagFromD.message, "UNIQUE_INCLUDED_FROM_D")
-
-    try ws.edit(rebuild: true) { (changes, _) in
-      changes.write(
-        """
-        // empty
-        """,
-        to: ws.testLoc("d_func").url
-      )
-      changes.write(
-        """
-        #include "unique.h"
-        """,
-        to: ws.testLoc("c_func").url
-      )
-    }
-
-    var receivedCorrectDiagnostic = false
-    for _ in 0..<Int(defaultTimeout) {
-      let diagsFromC = try await ws.testClient.nextDiagnosticsNotification(timeout: 1)
-      guard diagsFromC.diagnostics.count == 1, let diagFromC = diagsFromC.diagnostics.first else {
-        continue
-      }
-      guard diagFromC.severity == .warning, diagFromC.message == "UNIQUE_INCLUDED_FROM_C" else {
-        continue
-      }
-      receivedCorrectDiagnostic = true
-      break
-    }
-    XCTAssert(receivedCorrectDiagnostic)
-  }
-
-  private func clangBuildSettings(for uri: DocumentURI) -> FileBuildSettings {
-    return FileBuildSettings(compilerArguments: [uri.pseudoPath, "-DDEBUG"])
-  }
 }